Germany's two-year yield fell to minus 0.004pc at one point yesterday, meaning investors were prepared to give up any financial return in exchange for the safety of holding the investment - regarded as a "safe haven". It came after the US joined NATO and Poland in warning there is a risk that Russian president Vladimir Putin could send troops into Ukraine, and after Russia hit back at sanctions.

"There's a flight to safety and the fundamentals have deteriorated in Europe," said Allan von Mehren, chief analyst at Danske Bank in Copenhagen. (Bloomberg)